1. Technical Field
The present invention relates to a pretreatment agent for ink jet textile printing, an ink jet textile printing ink set including the pretreatment agent, and an ink jet textile printing method using the pretreatment agent.
2. Related Art
Various techniques are applied to recording processes for forming images on paper and other recording media according to image data signals. Among such techniques is an ink jet technique in which images are formed directly on a recording medium by ejecting an ink only onto desired image portions, using an inexpensive apparatus. In the ink jet technique, inks are efficiently used, and accordingly running cost can be reduced. In addition, little noise is produced when the ink jet technique is used, and the ink jet technique is thus advantageous as a recording method.
In recent years, approaches using an ink jet technique have been attempted for forming glossy images having high water fastness and rub fastness, and further high hiding power on the surface of a recording medium by ejecting a white pigment ink onto a recording medium.
For example, in a technique disclosed in JP-A-60-99081 (Example 1), a hard twist textile made of polyester fiber is pretreated by padding of a pretreatment agent (water repellent) of a fluorine-containing compound (Asahi Guard AG-710, manufactured by Asahi Glass) at a drawing rate of 62% and drying at 100° C. for 10 minutes, and a dye ink containing 4 parts of a dispersed dye, 1 part of a sizing agent sodium alginate (viscosity: 40 cps, produced by KIMICA) and 95 parts of ion-exchanged water is splayed to the pretreated hard twist textile by an on-demand ink jet method, thus producing a printed article.
Also, JP-A-2008-195767 (Paragraphs 0056, 0061 and 0069) discloses an aqueous white ink for ink jet textile printing. For preparing the aqueous white ink, 19 parts by mass of water is added to 36 parts by mass of a solution containing a specific polymer dispersant to yield a resin varnish for dispersing titanium oxide, and 45 parts by mass of titanium oxide is added to and mixed with the resin varnish, followed by dispersing the mixture in a wet mill to yield an aqueous white ink base (titanium oxide/dispersant=1/0.2) for ink jet textile printing. Then, to 33.3 parts by mass of the aqueous white ink base are added 33.3 parts by mass of nonionic acrylic resin emulsion (Mowinyl 966A, produced by Nichigo Mowinyl, solid content: 45% by mass) having a glass transition temperature of −30° C., 20 parts by mass of glycerol, 1 part by mass of acetylene glycol ethylene oxide adduct (Acetylenol E 100 produced by Kawaken Fine Chemicals), and 12.4 parts by mass of water. The materials are mixed and stirred to yield the aqueous white ink for ink jet textile printing.
However, when the techniques of the above-cited documents are applied to a white pigment ink, the whiteness of the resulting printed cloth may be very low, and the ink may not be reliably ejected.